The present invention relates to an apparatus for preventing troublesome load change shocks caused by a combustion engine used to propel a vehicle, whereby control commands for a power control element delivered by an accelerator pedal are transmitted with a time delay. An apparatus constructed in such a fashion is described in EP No. 0,155,993 F 02 D 11/10. By delaying the transmission of the control commands, a flattening or lengthening of the rise and fall times occurs.
It is known that in the case of automobiles with internal combustion engines, a so-called load change shock occurs during a change in load, i.e., on transition from engine braking to traction. Such a shock possibly leads to longitudinal vibrations of the vehicle otherwise known as jerking. This often occurs at low speeds of the internal combustion engine This phenomenon is determined essentially by the kinetic energy of the combustion engine and the drive train which, due to elasticities and clearances in the drive train, is set free and is partially transmitted to the vehicle's body during the load change. Therefore, the undesirable load change phenomena can be largely prevented if the kinetic energy built up during the load change is reduced to a minimum This occurs also in accordance with the state of the art cited, whereby the delayed transmission of the control command delivered by the accelerator pedal to the control element, e.g., a throttle valve or a control rod of an injection device, is limited to approximately 50% of the control range so that the operator, if necessary, can undertake a rapid acceleration of the vehicle.
From this would follow that the delay per se in the transmission of the accelerator pedal command would be undesirable. However, according to the state of the art it must be accepted within a relatively large control range in order to avoid or diminish to a tolerable measure the even more undesirable longitudinal dynamic instabilities of the vehicle.